Local snow transport and surface evolution processes in East Antarctica

In Antarctica, direct measurements of processes shaping the surface mass balance such as precipitation, accumulation and erosion, drifting and blowing snow, and sublimation, are sparse and challenging due to the extreme environment and related difficulties in measuring the variables of interest. An ongoing project, ‘Local Surface Mass Balance in East Antarctica’, is designed to address these processes at the local scale with the objective of relating near-surface atmospheric dynamics, drifting and blowing snow, snow properties, and resulting accumulation and erosion patterns. Two snow mass balance stations at Princess Elisabeth, Antarctica, (72S, 23E, 1380m.a.s.l.) are collecting data since December 2016, including standard meteorological instruments, snow particle counters and 3-D sonic anemometers for combined analysis of wind, turbulence and mass flux. Pre- and post-storm Terrestrial Laser Scans (TLS) record the resulting surface morphological changes. This contribution presents analysis and preliminary results of the turbulence and wind data to obtain vertically integrated mass flux estimates. Calculated surface roughness and friction velocities are used for establishing formulations of vertical profiles of drifting and blowing snow. Stability corrections, auto- and cross-correlation functions of wind and mass flux, as well as the lag-time between sonic anemometers and snow particle counters are investigated. It is shown which vertical profile shape leads to consistent mass flux estimates and how magnitudes of calculated mass fluxes compare to earlier estimates. The comparisons suggest that mass transport has rather been underestimated in early and several current studies.


Présenté à:
American Geophysical Union (AGU) Fall Meeting, Washington DC, December 2018
Année
2018
Laboratoires:




 Notice créée le 2019-02-21, modifiée le 2019-12-05


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